The charity sector has lost its way and seems to have given up on its founding notions. We are seeing a rather unseemly scramble for funding as charities seek to retain what they can of their state hand-outs while public services are cut. Or fundraisers, particularly those pesky chuggers, seemingly unacquainted with the causes for which they are apparently campaigning. Volunteers are expected to be as interested in their own employability as they are in helping other people. And the sector is apparently more interested in contracts and compacts than campaigns and causes.

I don't think we should blame the cuts or the "big society", as many in the sector do, for the problems charities face. The whole point of the big society – and the reason why I welcomed it at first – was that it proclaimed itself to be against an overbearing big state. We were told it was for the idea that people are able to do things for themselves, and to run their own lives without being "supported" all the time. But it seems that the charity sector doesn't see the big society in quite the same way, and the inference that it would not play the starring role in the coalition's big idea really rankled.

"We are the big society", it screamed. But is this true? At the same time that the sector has been claiming to represent us – to be the 99% (to borrow a phrase) – it has also boasted of its special relationship with the state. There is little pretence from sector leaders that it has any real independence, or indeed that this should be a problem. This "dual role" as both campaigner and service provider is described as a positive boon, allowing it influence that it wouldn't otherwise have. But it also means that charities don't stand for anything much anymore. The sector has no identity of its own, straddling both state and society. And so the promise of the big society, already held back by the prejudices of a parochial political culture, has become just another argument about funding, rooted in the charity sector's historical sense of entitlement.

To the extent that charities have increasingly focused on providing services rather than campaigning, no matter how good a job they do they are no longer charities in any meaningful sense. The Shelters, NSPCCs and RSPCAs of the charity world bear little resemblance to their former selves. They struggle with their dual identity as very sizeable public servants, on the one hand, and rather compromised campaigners, on the other. Is it any wonder that public trust in charities is reportedly "second only in volatility to its trust in banks"? Nobody knows what they're for any more. By shifting the focus of their work from tackling a social problem to managing their relationship with state bodies, they neglect what it is that gave them their reason for being in the first place.

My experience working with local government and the charity sector in one of the areas most affected by the August riots has been instructive. People have been coming forward, wanting to do something. The authorities have been going on about how uninterested and disengaged people are, and yet when they have come knocking on the door, are at a loss as to what to do with them. This has been interpreted by charity leaders as a problem created by the cuts – about not having the resources, and in particular the volunteer managers – to respond to this unexpected outpouring of community spirit. But I'm not so sure. I think it is their disjoint from the communities they claim to represent and serve that gets in the way of capturing that spirit.

The authorities – and I include the charity sector here – were taken aback that communities were rather more capable of building themselves than they'd imagined. That much-sought-after "sense of community" did what big society advocates and critics alike said it couldn't – it emerged of its own accord. The clean-ups were organised overnight on Facebook and Twitter by impromptu "pop-up" community groups. Volunteers got their brooms out before the smoke – both metaphorical and real – had settled, and then went their separate ways. Some wondered whether we were finally seeing the big society in action, but not in a good way.

One way or another, the big society is doomed. The charity sector doesn't have the resources to deliver it. We ordinary folk are not to be trusted with it. And, as some have noted, Cameron and his government have been talking a lot less about it anyway, as it has increasingly been seen as a byword for the cuts. This is a shame, not only because the big society preceded the cuts, but because its prospects should never have hinged on the cuts in the first place. It should have been a project for freeing up society, and creating a new culture of self-reliance, not a programme for government and its friends in the extended state sector to argue over. And yet, despite a sector seemingly intent on digging its own grave, we might try to breathe new life into the idea of charity. One more suited to today. And we might still resurrect some of the more appealing aspects of the big society, whatever we decide to call it. Maybe that way, rather than it being a clean-up for the charity sector, we can claim it for ourselves.

• Dave Clements is a writer on social policy and has worked for 12 years in local government. This is an edited version of a speech he gave at this weekend's Leeds Summat